When it comes to smoking on college campuses, the 25-foot rule is going out of style. Instead, there is zero tolerance.

A growing number of schools nationwide are going smoke-free, banning cigarettes, and in many cases, all tobacco, from their campuses. They are pairing it with stop-smoking resources for college students, who are in a critical age range for picking up or eschewing a lifelong smoking habit.

The result, proponents say, is fresher air on walkways and outside academic buildings — and, they're hoping, a healthier student body.

At least four schools in the Philadelphia region are among the latest working toward becoming completely tobacco-free — which means educating students, faculty, and staff and strategizing for a tough culture shift.

In 2015, 27 percent of students surveyed at the Community College of Philadelphia said they had smoked tobacco in the previous 30 days.

In the spring, after a smoke-free policy was implemented following a year and a half of preparation, 19.7 percent responded "yes" to the same question.

"We were really thrilled about that," said Kristy Shuda McGuire, an associate professor in biology who spearheaded the smoke-free transition.

She said they've tried to "make people feel good about it" by promoting positive interactions with those still smoking on campus, holding student events, and offering cessation resources, and deciding against enforcing the policy through fines or using security guards.

Now Temple, Lincoln, and Cheyney Universities are looking to follow CCP's lead, and joining nearly 150 other schools using grants from the American Cancer Society, Truth Initiative, and CVS Health Foundation, some of which go to Historically Black Colleges and Universities (HBCUs), community colleges, and schools that serve minorities.

"We have a lot of people who are very, very aware of the health issues around smoking," said Laura Siminoff, dean of the College of Public Health at Temple and chair of a task force formed last year to study going smoke-free.

"We also are aware of the fact that if you do not start smoking by the age of 25, you are almost undoubtedly never going to become a smoker, and that one of the prime times for people to start smoking is, sadly and unfortunately, when they go to university."

Temple, still in the beginning stages, has used the grant money to research how a tobacco-free campus might work.

Across the country, more than 1,900 colleges and universities in the nation are now nonsmoking — that's about 40 percent.

Just this year, the California State University system banned smoking at its 23 campuses, and the University of Texas system's 14 campuses went tobacco-free. In January, a task force was formed at Pennsylvania State University to study going smoke-free.

Drexel and La Salle Universities are smoke-free; Villanova allows smoking 25 feet from campus buildings. At Rutgers University, smokers must be 30 feet from buildings. The University of Pennsylvania calls itself a "tobacco-less" campus but prohibits smoking only  within 20 feet of building entrances and in various outdoor spaces.

Some students smoking at Temple around lunchtime Friday said they didn't think a ban would be easy to enforce on the urban campus.

"I would still smoke," said junior Kelly Dool, who was sitting on a sunny bench outside Fox School of Business having a cigarette as she looked at her planner. "I've been smoking for like 11 years; it's not going to stop. Especially going here — I need to smoke."

Before transferring to Temple, she said, she attended Delaware County Community College, where smoking is banned, but she and her friends still found a hiding spot to light up on campus, where they would call out a code word if a security guard was coming.

Another junior sitting outside with a cigarette, who declined to give her name, said she thought a ban would be "unrealistic compared to the real world. They're kind of creating a 'safe space' that's not necessary."

Four states have laws requiring smoke-free campuses at public institutions: Arkansas, Illinois, Iowa, and Louisiana, according to Americans for Nonsmokers' Rights. (Iowa also mandates no smoking at private ones.)

As of July, 10 institutions in New Jersey and 18 in Pennsylvania had gone smoke-free; many also had bans on tobacco, e-cigarettes, or marijuana, according to the group's list.

Lincoln University started working on a policy in 2015 and has spent two years preparing to implement it and getting the smoke-free message out. It will begin enforcing the policy — potentially including fines — in January.

"The smokers' comments helped a great deal; they helped us be sensitive," said Lenetta Lee, the school's dean of students. "But for the most part, overwhelmingly, students, faculty, and staff were ready to move forward with the tobacco-free policy."

Lee said she's heard people still lighting up on campus say they are trying to quit before January, and the school is providing resources to help. Lincoln will convert former smoking areas into gardens.

"I'm anxious to see what January brings when it's actually being enforced," she said. "It's been a lot of positive talk."

The strategies generally include educating students and faculty, setting up smoking-cessation programs, and figuring out the logistics of actually enforcing the bans.

"There's a lot of people down here who smoke," said Tim Gray, a Temple freshman who was smoking on the sidewalk Friday. He said a smoke-free campus would not encourage him to quit, especially because he would still want to light up at social gatherings. He didn't think going tobacco-free was realistic for the university. "I think it would just be a lot more cigarette butts."

At CCP, organizers put up signs, made wallet cards advertising stop-smoking resources, and held no-smoking events for students, Shuda McGuire said. This semester, four student interns will tackle more projects: producing a video documenting student attitudes about smoking, creating educational resources for students, studying where signs are still needed on campus, and making a public art piece out of tobacco materials.

"We wanted this to encourage any member of the community to feel empowered to enforce the policy, so we created these wallet cards," she said. They've held training sessions on how to distribute them to on-campus smokers and to make it "a brief interaction, positive instead of confrontational."

Cheyney University on Saturday introduced a program that will be launched with the grant money that the school just received. Organizers are hoping to help students remember that tobacco includes hookah and e-cigarettes and educating them about the reach of the tobacco industry in urban neighborhoods, said Thom Nixon, associate director of community living and judicial affairs at the HBCU.

"There's an overwhelming number of billboards advertising alcohol and also tobacco products in our neighborhoods. … They target our audience," Nixon said. "We're looking at it from a health perspective; we're looking at it from a social justice perspective.

"We're trying to look at ways we can find healthy outlets for our students in terms of developing good habits while they're here at school, so when they go out into the work world they can deal with those stresses that come up just in daily living."